I'm attempting the process of creating a Disaster Recovery Disk for the first time but the process is not completing - I get the error Can't continue execution, error -1101 (file/directory not found)
Retrospect 11.5.0.190
Windows 8.0
I've downloaded and installed the Windows ADK kit for Windows 8.0 and pointed the Disaster Recovery Disk process at the copype.cmd file.
Any idea what I'm missing?

I have been getting exactly this symptom when trying to activate the Client version 11.5.0(137) on Mac OS X 10.9 and now 10.10 .
Server version is Retrospect Desktop 9.5.3.103 on Windows, which is working absolutely fine for another Mac client (on OS X 10.9) and three Windows systems.
So I'm using Time Machine instead.

SOLVED
thank you Scillonian, that put me on the right track.
Even when running the Retrospect Client Installer immediately after the Vista Installer completes (i.e. before any automatic updates) I was getting the same error.
However, having found advice online about right-clicking the setup.exe in order to to Run as Administrator, I actually found that simply by running the setup.exe file rather than the Retrospect Client 9.0 Installer Package allowed the process to complete - after confirming a dialogue window concerning permissions.
Phew!

I'm attempting to install Retrospect Client 9.0 on a virtual machine running Vista Home Premium; hardware is a Mac Pro
I have installed Vista and let it run all the security updates.
As I cannot successfully complete the Install, I cannot run any updates.
I have also tried the 7.6 installer.
The steps I am taking and problem I am experiencing is identical to that in the opening post - almost as soon as the installation process starts an Error appears with the message During the installation on the client machine an error appears "RegCreateKey(HKEY_LOCAL_MACHINE, "SOFTWARE\Dantz\RetrospectClient\5.0\Install", ...) returned 5"
As the link you posted above to Microsofts error messages says : The information on this page is intended to be used by programmers so that the software they write can better deal with errors. If you are an end-user that is experiencing difficulty with an application you are installing or running, contact customer support for the software that is displaying the error message.]
I have been successfully using several different versions of Retrospect for many years now, on a mix of Windows PCs (physical and virtual) and Macs in our office, so I am baffled as to how the Client Installer can fall at the first hurdle in this case.